766. Toeplitz Matrix

LeetCode Toeplitz Matrix【Easy】

• A matrix is Toeplitz if every diagonal from top-left to bottom-right has the same element.
• Now given an M x N matrix, return True if and only if the matrix is Toeplitz.

Example 1:

Input:
matrix = [
  [1,2,3,4],
  [5,1,2,3],
  [9,5,1,2]
]
Output: True
Explanation:
In the above grid, the diagonals are:
"[9]", "[5, 5]", "[1, 1, 1]", "[2, 2, 2]", "[3, 3]", "[4]".
In each diagonal all elements are the same, so the answer is True.

Example 2:

Input:
matrix = [
  [1,2],
  [2,2]
]
Output: False
Explanation:
The diagonal "[1, 2]" has different elements.

Note:

1. matrix will be a 2D array of integers.
2. matrix will have a number of rows and columns in range [1, 20].
3. matrix[i][j] will be integers in range [0, 99].

题目很简单，直接获取矩阵中的值，然后和下一个值进行比对，需要注意的是每行对比的元素可以除去最后一个。

  public static boolean isToeplitzMatrix(int[][] matrix) {
      //行
      int row=matrix.length;
      //列
      int col = matrix[0].length;
      /**
       * 反面情况
       *
       */
      for (int i = 0; i < row-1; i++) {
          for (int j=0;j<col-1;j++){
              if(matrix[i][j]!=matrix[i+1][j+1]){
                  return false;
              }
          }
      }
      return true;
  }